CN108502899B

CN108502899B - Cu-SAPO molecular sieve, synthetic method thereof and application thereof in denitration reaction

Info

Publication number: CN108502899B
Application number: CN201710107559.8A
Authority: CN
Inventors: 向骁; 田鹏; 刘中民; 曹磊
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2017-02-27
Filing date: 2017-02-27
Publication date: 2021-06-08
Anticipated expiration: 2037-02-27
Also published as: CN108502899A

Abstract

The invention provides a Cu-SAPO molecular sieve with CHA and GME intergrowth crystal phases, a synthetic method thereof and application thereof in denitration reaction. The Cu-SAPO molecular sieve is characterized in that an XRD diffraction spectrum of the molecular sieve shows the coexistence of broad peaks and sharp peaks, and an inorganic framework has the following chemical compositions: wCu- (Si)_xAl_yP_z)O₂Wherein: x, y and z represent the mole fractions of Si, Al and P, and the ranges are 0.01 to 0.28 for x, 0.35 to 0.55 for y, 0.28 to 0.50 for z, and 1 for x + y + z, and w is per mole (Si, Al and P)_xAl_yP_z)O₂The mole number of Cu is 0.001-0.124. The synthesized molecular sieve can be used as NO_xAnd (4) selecting a catalyst for reduction removal reaction.

Description

Cu-SAPO molecular sieve, synthetic method thereof and application thereof in denitration reaction

Technical Field

The invention relates to a novel copper-containing SAPO molecular sieve, a synthesis method and application thereof in denitration reaction.

Background

NOx is one of main atmospheric pollutants, can cause a plurality of environmental problems such as acid rain, photochemical smog and the like, and is seriously harmful to human health, nitrogen oxide pollution is mainly caused by the emission of mobile source automobile tail gas and the emission of fixed source factory waste gas, and the treatment method of NOx pollution is NH₃Urea or hydrocarbon is used as reductant to perform selective catalytic reduction reaction to convert it into harmless nitrogen. The traditional denitration catalyst is mainly a V-Ti-W system, but with the wide adoption of lean burn technology in engine technologyThe emission temperature of lean-burn exhaust is reduced, the application range of the catalyst of a V-Ti-W system at a narrow temperature cannot meet the requirement, and the potential possibility of causing environmental pollution limits the application of the catalyst. Molecular sieve catalytic systems are becoming the current focus of research. Of the molecular sieve system catalysts, copper-based catalysts and iron-based catalysts are representative of two systems, and the copper-based catalysts show excellent low-temperature activity, but too high loading can cause severe NH at high temperature section₃And (4) carrying out oxidation reaction. The iron-based catalyst has excellent high-temperature activity, but the low conversion rate in a low-temperature section limits the application of the iron-based catalyst in certain fields.

In 1986, Iwamoto et al reported Cu for the first time²⁺Exchanged ZSM-5 with direct decomposition of NO to N₂And O₂In the following research, since researchers pay more attention to the SCR reaction using hydrocarbon as a reducing agent, Fe-ZSM-5 is gradually becoming the next research focus, and compared with an oxide catalyst, a molecular sieve system catalyst has the advantages of a wider reaction temperature window, good thermal stability, and strong sulfur poisoning resistance at high temperature, but they also have some problems, such as poor high-temperature hydrothermal stability, poor low-temperature sulfur resistance, and the like.

The small pore molecular sieves such as SSZ-13 and SAPO-34 are used as carrier materials, can effectively improve the high-temperature hydrothermal stability of the catalyst, and have high NO conversion activity and high N in a wider temperature range when copper is loaded as an active metal₂And (4) selectivity. Although the sulfur-sensitive oil has the problems of sensitivity to sulfur and the like, the problem is gradually solved along with the improvement of the quality of oil products.

In general, the synthesis of the SAPO molecular sieve needs organic amine/ammonium as a structure directing agent and is obtained by hydrothermal or solvothermal synthesis. Innovations in the synthesis process and the selection of templating agents have a crucial impact on the control of product structure and performance. ,

Cu-SAPO-18 and Cu-SAPO-34 can be synthesized by one step by taking a copper amine complex as a template agent. The Cu-SAPO catalyst synthesized by the one-step method simplifies the preparation process of the catalyst and has important significance.And the Cu-SAPO type catalyst synthesized by the one-step method shows excellent NH₃SCR catalytic activity, as well as the tunable nature of the composition, have certain prospects for industrial applications.

The invention provides a method for synthesizing a Cu-SAPO molecular sieve catalyst by a one-step method with controllable Cu content, shows excellent deNOx catalytic activity and has potential application value.

Disclosure of Invention

The invention aims to provide a Cu-SAPO molecular sieve with a GME and CHA eutectic structure.

The novel molecular sieve synthesized by the invention has the characteristic of coexistence of broad peaks and sharp peaks, and the XRD diffraction pattern of the novel molecular sieve presents the characteristics of coexistence of broad peaks and sharp peaks (microporus and mesopore Materials,30(1999)335 and 346; official website of International molecular Sieve Associationhttp://www.iza-structure.org/databases/Catalog/ABC 6.pdf) The spectra of the silica-alumina zeolite with GME/CHA intergrowth structure have similarity. We analyzed this class of molecular sieves as novel SAPO molecular sieves with GME/CHA intergrowth.

According to an embodiment of the present invention, there is provided a Cu-SAPO molecular sieve having a CHA and GME intergrowth phase, characterized in that said molecular sieve has an X-ray diffraction pattern comprising at least the following diffraction peaks:

TABLE 1

The inorganic framework of the molecular sieve has the following chemical composition: wCu- (Si)_xAl_yP_z)O₂Wherein: x, y and z represent the mole fractions of Si, Al and P, and the ranges are 0.01 to 0.28 for x, 0.35 to 0.55 for y, 0.28 to 0.50 for z, and 1 for x + y + z, and w is per mole (Si, Al and P)_xAl_yP_z)O₂The mole number of Cu is 0.001-0.124.

The anhydrous chemical composition of a molecular sieve containing a templating agent can be expressed as: wCu mR1 nR3 (Si)_xAl_yP_z)O₂Wherein: r1 is diisopropanolamine orDiethanolamine, R3 is trimethylamine; m is (Si) per mole_xAl_yP_z)O₂Wherein the mole number of the R1 template agent and n is per mole (Si)_xAl_yP_z)O₂Wherein the mole number of the R3 template agent, m is 0.01-0.20, and n is 0.01-0.20; x, y and z represent mole fractions of Si, Al and P respectively, and the ranges of x is 0.01-0.28, y is 0.35-0.55, z is 0.28-0.50, and x + y + z is 1; w is per mole (Si)_xAl_yP_z)O₂The mole number of Cu is 0.001-0.124. In certain embodiments, m can range from 0.02 to 0.15; n can be 0.05 to 0.20; x can be 0.10-0.28; y can be 0.40 to 0.50; z can be 0.28-0.45; w may be 0.005 to 0.100.

The invention also aims to provide a synthesis method of the Cu-SAPO molecular sieve, which is characterized by comprising the following steps:

a) mixing a copper source, deionized water, template agents R1 and R2, a silicon source, an aluminum source and a phosphorus source in proportion to obtain an initial gel mixture with the following molar ratio:

Cu/Al₂O₃＝0.01～0.25；

SiO₂/Al₂O₃＝0.05～2.0；

P₂O₅/Al₂O₃＝0.5～1.5；

H₂O/Al₂O₃＝8～40；

R1/Al₂O₃＝5～20；

R2/Al₂O₃＝0.1～1.5；

wherein, R1 is Diisopropanolamine (DIPA) or Diethanolamine (DEOA); r2 is one or more of Trimethylamine (TMA), benzyltrimethylammonium chloride (BTACL) and benzyltrimethylammonium hydroxide (BTAOH).

The specific batching sequence can be as follows: the copper source is first mixed with water to dissolve, then R1 and R2 are added and stirred at room temperature for 0.5-5 h. And then, sequentially adding an aluminum source, a silicon source and a phosphorus source into the mixed solution, and stirring the mixed gel at room temperature for 1-5 h.

b) And (b) putting the initial gel mixture obtained in the step a) into a high-pressure synthesis kettle, sealing, heating to 120-150 ℃, pre-crystallizing for 0.5-6h, then heating to 160-220 ℃, and crystallizing for 5-72 h.

c) After crystallization is finished, separating, washing and drying the solid product to obtain the molecular sieve.

Wherein, the silicon source in the step a) is one or more selected from silica sol, active silica, orthosilicate ester and metakaolin; the aluminum source is selected from one or more of aluminum salt, activated alumina, pseudoboehmite, aluminum alkoxide and metakaolin; the phosphorus source is selected from one or more of orthophosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate, organic phosphide and phosphorus oxide; the copper source is selected from Cu (OAc)₂,CuSO₄,Cu(NO₃)₂,CuCl₂One or more of them.

The crystallization process in step b) is performed in a static or dynamic state.

Preferably, said step a) of SiO in the initial gel mixture₂/Al₂O₃＝0.20～1.8。

Preferably, said step a) of P in the initial gel mixture₂O₅/Al₂O₃＝0.8～1.5。

Preferably, said step a) of R1/Al in the initial gel mixture₂O₃＝5.0～10。

Preferably, said step a) of R2/Al in the initial gel mixture₂O₃＝0.25～1.0。

The organic templates in R2, namely benzyltrimethylammonium chloride (BTACL) and benzyltrimethylammonium hydroxide (BTAOH), are decomposed during the synthesis of the molecular sieve to generate trimethylamine, and the trimethylamine enters into a pore cage of the molecular sieve.

In the above method for synthesizing a molecular sieve, when R1 is diethanolamine, the molar ratio of R1/R2 is preferably in the range of 4 to 16; when R1 is diisopropanolamine, the preferred crystallization temperature is 160-195 ℃.

It is a further object of the present application to provide a NO_xSelective reduction removal reactionThe catalyst is obtained by roasting the molecular sieve and/or the molecular sieve synthesized by the method in air at 550-700 ℃.

The invention can produce the beneficial effects that:

(1) a novel Cu-SAPO molecular sieve is provided.

(2) The prepared molecular sieve can be used as a catalyst for catalytic removal reaction of nitrogen oxides and shows good catalytic performance.

Drawings

FIG. 1 is an XRD pattern of the product synthesized in example 1

FIG. 2 is a Scanning Electron Micrograph (SEM) of a synthesized product of example 1

FIG. 3 NH of example 10 and comparative example 2₃Evaluation of SCR reaction

FIG. 4 is NH for catalysts with different copper contents (examples 10-12)₃Comparison of results of evaluation of SCR reactions

FIG. 5 shows NH before and after the high-temperature hydrothermal treatment of the sample of example 1 (examples 10 and 13)₃Comparison of results of evaluation of SCR reactions

FIG. 6 is a sample XRD characterization of comparative examples 3-8

Detailed Description

The invention is further illustrated by the following examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers. In the case where no specific description is given, the raw materials used in the present application are all purchased from commercial sources and used without any special treatment.

Without specific description, the test conditions of the present application are as follows:

the elemental composition was determined using a Philips Magix 2424X-ray fluorescence Analyzer (XRF).

FT-IR was collected using a BRUKER TENSOR 27 instrument, Germany.

X-ray powder diffraction phase analysis (XRD) an X' Pert PRO X-ray diffractometer from pananace (PANalytical) of the netherlands, Cu target, K α radiation source (λ ═ 0.15418nm), voltage 40KV, current 40mA were used.

The specific surface area and pore size distribution of the sample were measured using a physical adsorption apparatus model ASAP 2020, Micromeritics, usa. Before analysis, the sample is heated and pretreated for 6h at 350 ℃ in a vacuum manner, and the free volume of the sample tube is measured by taking He as a medium. When analyzing the sample, the physical adsorption and desorption measurements were carried out at a liquid nitrogen temperature (77K) using nitrogen as the adsorption gas. Determining the specific surface area of the material by adopting a BET formula; using relative pressure (P/P)₀) N at 0.99₂The total pore volume of the material was calculated. The micropore surface area and micropore volume were calculated by the t-plot method. When calculating, N₂The cross-sectional area of the molecule was taken to be 0.162nm²。

SEM morphology analysis was performed using a Hitachi (SU8020) scanning electron microscope.

Carbon nuclear magnetic resonance (¹³C MAS NMR) analysis an infinite plus 400WB solid nuclear magnetic spectrometer from Varian corporation, usa was used, and the operating magnetic field strength was 9.4T using a BBO MAS probe.

The CHN element analysis was carried out by using a Vario EL Cube element analyzer manufactured by Germany.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1

The mol ratio and crystallization conditions of the raw materials are shown in table 2, and the specific batching process is as follows: the copper source was first dissolved in water, then R1 and R2 were added and stirred at room temperature for 2 h. Subsequently, an aluminum source, a silicon source and a phosphorus source were sequentially added to the mixed solution, and the mixed gel was stirred at room temperature for 5 hours. And (3) putting the obtained initial gel mixture into a high-pressure synthesis kettle, sealing, putting the reaction kettle into an oven, heating to 140 ℃, pre-crystallizing for 5 hours, and heating to 180 ℃ for dynamic crystallization for 48 hours. And after crystallization is finished, centrifuging and washing the solid product, and drying in air at 100 ℃ to obtain the molecular sieve raw powder sample. When the sample is subjected to XRD analysis, the peak shape shows the characteristic of coexistence of broad peaks and peaks, the XRD diffraction pattern is shown in figure 1, and the XRD diffraction data is shown in table 3. After the sample is roasted to remove the template agent, the specific surface area and the pore volume are measured, and the sample has high BET specific surface area (630 m)²g^-1) And a large pore volume (0.28 cm)³g^-1) Wherein the specific surface area and the volume of the micropores calculated according to the t-plot method are 577m respectively²g^-1And 0.24cm³g^-1。

The scanning electron micrograph of the obtained sample is shown in FIG. 2, and it can be seen that the morphology of the obtained sample is hexagonal sheet, the surface of the crystal grains is rough, and the particle size range is 3-5 μm.

Table 2: molecular sieve synthesis burdening and crystallization condition table

^aThe pre-crystallization condition is 140 ℃ and 5h

^bThe pre-crystallization condition is 120 ℃,0.5h

^cThe pre-crystallization condition is 150 ℃ and 6h

^dThe pre-crystallization condition is 130 ℃ for 4h

Table 3 XRD results for the sample of example 1

Example 2

The specific compounding ratio and crystallization conditions are shown in Table 2, and the specific compounding process is the same as that of example 1.

XRD analysis of the synthesized samples gave representative data results as shown in Table 4.

The scanning electron micrograph shows that the morphology of the obtained sample is similar to that of the sample in example 1.

Table 4 XRD results for the sample of example 2

Example 3

XRD analysis of the synthesized samples gave representative data results as shown in Table 5.

Table 5 XRD results for example 3 sample

Examples 4 to 8

The specific compounding ratio and crystallization conditions are shown in Table 2, and the specific compounding process is the same as that of example 1. XRD analysis of the synthesized samples showed results for XRD data for examples 4 and 8 close to those in Table 3, for examples 5 and 6 close to those in Table 4, and for example 7 close to those in Table 5.

The silicoaluminophosphate molecular sieves provided in examples 1-8 had a significantly higher content of the GME crystalline phase than the CHA crystalline phase as compared to the diffraction pattern of the GME/CHA intergrown silica alumina zeolite crystalline phase at different ratios as given in the official website of the international molecular sieve association.

Example 9

The samples of powders from examples 1 to 8 were subjected to¹³C MAS NMR analysis by reaction with diisopropanolamine, diethanolamine and trimethylamine¹³Comparing the standard spectrum of the C MAS NMR, finding that a sample synthesized by taking diisopropanolamine as a solvent simultaneously has the resonance peaks of diisopropanolamine and trimethylamine, and a sample synthesized by taking diethanolamine as a solvent simultaneously has the resonance peaks of diethanolamine and trimethylamine. Quantitative analysis is carried out according to the specific and non-coincident NMR peaks of the two substances, and the proportion of the two substances is determined.

The molecular sieve product bulk elemental composition was analyzed by XRF and the CHN elemental analysis was performed on the raw powder samples of examples 1-8. Integrated CHN elemental analysis, XRF and¹³the composition of the molecular sieve raw powder obtained from the results of C MAS NMR analysis is shown in Table 6:

TABLE 6 compositions of sample base powders of examples 1-8

Samples of the raw powders of examples 1-8 were separately mixed with potassium bromide, ground and tabletted for FT-IR characterization, all at 637cm^-1A very distinct characteristic vibration absorption peak attributed to the double six-membered ring appears, indicating the presence of the double six-membered ring in the sample.

Example 10

The sample obtained in example 1 was calcined at 650 ℃ for 2h, the template was removed, and the residue was used for NH₃Selective reduction removal of NO_xThe catalytic performance of the reaction was characterized. The specific experimental procedures and conditions were as follows: after the calcination, the sample was pressed into a sheet and sieved, and 0.1g of a 60 to 80 mesh sample was weighed and mixed with 0.4g of quartz sand (60 to 80 mesh), and the mixture was charged into a fixed bed reactor. Introducing nitrogen at 600 ℃ for activation for 40min, then cooling to 120 ℃ to start reaction, and raising the temperature to 550 ℃ by program. The raw material gas for reaction is: NO: 500ppm, NH₃：500ppm，O₂：5％，H₂O：5％，N₂As an equilibrium gas, the gas flow rate was 300 mL/min. The reaction off-gas was analyzed by on-line FTIR using a Bruker model Tensor 27 instrument, and the results are shown in FIGS. 3 and 4. It can be seen that the NO conversion reaches 55% at 150 ℃ and is greater than 90% over the broader temperature range of 200 ℃ and 550 ℃. Similarly, the samples obtained in examples 2 to 7 also exhibited better results after the same treatments as those of the sample in example 1Selective reduction removal of NO_xCatalytic performance.

Example 11

The sample obtained in example 7 was calcined at 650 ℃ for 2h, the template was removed, and the residue was used for NH₃Selective reduction removal of NO_xThe catalytic performance of the reaction was characterized. The specific experimental procedures and conditions were as follows: after the calcination, the sample was pressed into a sheet and sieved, and 0.1g of a 60 to 80 mesh sample was weighed and mixed with 0.4g of quartz sand (60 to 80 mesh), and the mixture was charged into a fixed bed reactor. Introducing nitrogen at 600 ℃ for activation for 40min, then cooling to 120 ℃ to start reaction, and raising the temperature to 550 ℃ by program. The raw material gas for reaction is: NO: 500ppm, NH₃：500ppm，O₂：5％，H₂O：5％，N₂As an equilibrium gas, the gas flow rate was 300 mL/min. The reaction off-gas was analyzed by on-line FTIR using a model Tensor 27 instrument from Bruker, and the reaction results are shown in FIG. 4.

Example 12

The sample obtained in example 4 was calcined at 650 ℃ for 2h, the template agent was removed, and the residue was used for NH₃Selective reduction removal of NO_xThe catalytic performance of the reaction was characterized. The specific experimental procedures and conditions were as follows: after the calcination, the sample was pressed into a sheet and sieved, and 0.1g of a 60 to 80 mesh sample was weighed and mixed with 0.4g of quartz sand (60 to 80 mesh), and the mixture was charged into a fixed bed reactor. Introducing nitrogen at 600 ℃ for activation for 40min, then cooling to 120 ℃ to start reaction, and raising the temperature to 550 ℃ by program. The raw material gas for reaction is: NO: 500ppm, NH₃：500ppm，O₂：5％，H₂O：5％，N₂As an equilibrium gas, the gas flow rate was 300 mL/min. The reaction off-gas was analyzed by on-line FTIR using a BRUKER TENSOR 27 model instrument. The reaction results are shown in FIG. 4.

Example 13

The sample obtained in the example 1 is roasted at a high temperature of 650 ℃ for 2h, after the template agent is removed, hydrothermal aging treatment is carried out at 800 ℃, the water vapor content is 100 percent, the treatment time is 24h, and after the treatment is finished, drying is carried out at 100 ℃.

The relative crystallinity of the sample is determined by an XRD method, and the crystallinity of the sample after water treatment is 90% of that of the sample in example 1, which shows that the sample prepared in example 1 has higher hydrothermal stability and can better maintain the structural integrity after water treatment.

For NH₃Selective reduction removal of NO_xThe catalytic performance of the reaction was characterized. The specific experimental procedures and conditions were as follows: the samples were pressed into tablets and sieved, 0.1g of 60 to 80 mesh sample was weighed and mixed with 0.4g of quartz sand (60 to 80 mesh) and charged into a fixed bed reactor. Introducing nitrogen at 600 ℃ for activation for 40min, then cooling to 120 ℃ to start reaction, and raising the temperature to 550 ℃ by program. The raw material gas for reaction is: NO: 500ppm, NH₃：500ppm，O₂：5％，H₂O：5％，N₂As an equilibrium gas, the gas flow rate was 300 mL/min. The reaction off-gas was analyzed by on-line FTIR using a BRUKER TENSOR 27 model instrument. The reaction results are shown in FIG. 5.

Comparative example 1:

10g of the molecular sieve raw powder sample obtained in example 8 was used as a precursor, and the mixture was heated to 600 ℃ at a rate of 2 ℃/min and baked at a constant temperature for 4 hours to remove the organic template and water contained therein.

The roasted sample is put into 3.66mol/L ammonium nitrate aqueous solution according to the solid-liquid ratio (mass ratio) of 1:10, stirred for five minutes, and then heated to 80 ℃ for ion exchange for 2 hours. Then centrifugally separating, washing with deionized water for three times, and drying at 80 ℃ to obtain NH₄ ⁺A type molecular sieve.

Adding 7g of NH₄ ⁺The type molecular sieve is added with 0.03mol/L of Cu (CH) according to the solid-to-liquid ratio of 1:25₃COO)₂·H₂O solution, stirring for 5 minutes, and raising the temperature to 50 ℃ for ion exchange for 4 hours. Then, the mixture was centrifuged, washed 3 times with deionized water, and dried at 80 ℃ to obtain a sample designated as Cu-8/T. The XRF elemental analysis showed a copper oxide content of the product of 3%, similar to that of example 1. By using N₂The specific surface areas and pore volumes of the samples of the calcination type example 8 and the Cu-8/T samples were measured by physical adsorption, and the specific surface areas and pore volumes of micropores were calculated by the T-plot method. The specific surface area of micropores and the volume of micropores in the sample of example 8 were 596m, respectively²g^-1And 0.26cm³g^-1The specific surface area and the volume of each micropore were 554m for the Cu-8/T sample²g^-1And 0.25cm³g^-1. These results show that the catalyst prepared according to the method of example 1 can better maintain the regularity of the skeletal structure of the sample.

Comparative example 2

The sample obtained in comparative example 1 was calcined at 650 ℃ for 2h and used as NH₃Selective reduction removal of NO_xA catalyst for the reaction. The specific experimental procedures and conditions were as follows: after the calcination, the sample was pressed into a sheet and sieved, and 0.1g of a 60 to 80 mesh sample was weighed and mixed with 0.4g of quartz sand (60 to 80 mesh), and the mixture was charged into a fixed bed reactor. Introducing nitrogen at 600 ℃ for activation for 40min, then cooling to 120 ℃ to start reaction, and raising the temperature to 550 ℃ by program. The raw material gas for reaction is: NO: 500ppm, NH₃：500ppm，O₂：5％，H₂O：5％，N₂The total flow rate of gas for the balance gas was 300 mL/min. The total space velocity GHSV of the reaction is 180000h^-1. The reaction off-gas was analyzed by on-line FTIR using a BRUKER TENSOR 27 model instrument. The specific results are shown in FIG. 3.

Comparative example 3

The raw materials used for synthesis are 0.6mol of triethylamine, 0.03mol of trimethylamine and 0.009mol of CuCl₂0.1mol of pseudo-boehmite, 0.08mol of orthophosphoric acid, 0.08mol of silica sol and 1.5mol of water. The copper source was first dissolved in water, then trimethylamine and triethylamine were added and stirred at room temperature for 2 h. And then, sequentially adding an aluminum source, a silicon source and a phosphorus source into the mixed solution, stirring the mixed gel at room temperature for 5 hours to prepare gel, and transferring the gel into a stainless steel reaction kettle. After the reaction kettle is placed in an oven, the temperature is raised to 200 ℃ at the speed of 2 ℃/min, and the crystallization is carried out for 36 hours under the rotating condition. And after crystallization is finished, centrifuging and washing the solid product, and drying in air at 100 ℃ to obtain the molecular sieve raw powder sample. XRD analysis is carried out on the sample, the sample is SAPO-34 molecular sieve, and the XRD analysis result is shown in figure 6.

Comparative example 4

The specific molar ratio of ingredients, raw materials and crystallization conditions are shown in Table 7, the compounding process is the same as that of comparative example 3, the synthesized sample is a lamellar phase, and the XRD result is shown in FIG. 6.

Comparative example 5

The specific molar ratio of the ingredients, the raw materials and the crystallization conditions are shown in Table 7, the ingredients are prepared in the same manner as in comparative example 3, the synthesized sample is a physical mixture of SAPO-34 and SAPO-5, and XRD results are shown in FIG. 6.

Comparative example 6

The specific molar ratios of ingredients, raw materials and crystallization conditions are shown in Table 7, the compounding process is the same as that of comparative example 3, a physical mixture of DNL-6 (SAPO molecular sieve with RHO structure) with a small amount of SAPO-34 is synthesized, and XRD results are shown in FIG. 6.

Comparative example 7

The specific molar ratio of the ingredients, the raw materials and the crystallization conditions are shown in Table 7, the ingredients are prepared in the same manner as in comparative example 3, the synthesized sample is a physical mixture of SAPO-5 and SAPO-34, and XRD results are shown in FIG. 6.

Comparative example 8

The specific molar ratio of ingredients, raw materials and crystallization conditions are shown in Table 7, the compounding process is the same as that of comparative example 3, the synthesized sample is amorphous, and the XRD analysis result is shown in FIG. 6.

Table 7: comparative examples 3 to 8 Synthesis of ingredients and crystallization conditions

The synthesis results of comparative examples 3-8 show that the Cu-SAPO molecular sieves with GME and CHA eutectic of the present patent application can be obtained only under specific template combination and proper crystallization conditions.

Although the present application has been described with reference to preferred embodiments, it is not intended to limit the scope of the claims, and many possible variations and modifications may be made by one skilled in the art without departing from the spirit of the application.

Claims

1. A silicoaluminophosphate molecular sieve containing copper having a intergrowth crystalline phase of CHA and GME, wherein said molecular sieve has an X-ray diffraction pattern comprising at least the following diffraction peaks:

wherein the molecular sieve comprises an anhydrous chemical composition of the template represented by:

wCu·mR1·nR3·(Si_xAl_yP_z)O₂wherein: r1 is diisopropanolamine or diethanolamine, R3 is trimethylamine; m is (Si) per mole_xAl_yP_z)O₂Wherein the mole number of the R1 template agent and n is per mole (Si)_xAl_yP_z)O₂Wherein the mole number of the R3 template agent, m is 0.01-0.20, and n is 0.01-0.20; x, y and z represent mole fractions of Si, Al and P respectively, and the ranges of x is 0.01-0.28, y is 0.35-0.55, z is 0.28-0.50, and x + y + z is 1; w is per mole (Si)_xAl_yP_z)O₂The mole number of Cu is 0.001-0.124.

2. The molecular sieve of claim 1, wherein the inorganic framework of the molecular sieve has the following chemical composition: wCu- (Si)_xAl_yP_z)O₂Wherein: x, y and z represent the mole fractions of Si, Al and P, and the ranges are 0.01 to 0.28 for x, 0.35 to 0.55 for y, 0.28 to 0.50 for z, and 1 for x + y + z, and w is per mole (Si, Al and P)_xAl_yP_z)O₂The mole number of Cu is 0.001-0.124.

3. A method of synthesizing the molecular sieve of any of claims 1-2, comprising the steps of:

Cu/Al₂O₃＝0.01～0.25；

SiO₂/Al₂O₃＝0.05～2.0；

P₂O₅/Al₂O₃＝0.5～1.5；

H₂O/Al₂O₃＝8～40；

R1/Al₂O₃＝5～20；

R2/Al₂O₃＝0.1～1.5；

wherein R1 is diisopropanolamine or diethanolamine; r2 is any one or a mixture of any more of trimethylamine, benzyltrimethylammonium chloride and benzyltrimethylammonium hydroxide;

b) putting the initial gel mixture obtained in the step a) into a high-pressure synthesis kettle, sealing, heating to 120 ℃ and 150 ℃, pre-crystallizing for 0.5-6h, then heating to 160-220 ℃, and crystallizing for 5-72 h;

c) and after crystallization is finished, separating, washing and drying the solid product to obtain the molecular sieve.

4. A method according to claim 3, characterized in that the dosing process of step a) is as follows: the copper source is first mixed with water, then R1 and R2 are added and stirred at room temperature for 0.5-5h, then aluminum source, silicon source and phosphorus source are added to the mixture in sequence, and the mixed gel is stirred at room temperature for 1-5 h.

5. The method according to claim 3, wherein the silicon source in step a) is selected from one or more of silica sol, active silica, orthosilicate ester and metakaolin; the aluminum source is selected from one or more of aluminum salt, activated alumina, pseudoboehmite, aluminum alkoxide and metakaolin; the phosphorus source is selected from one or more of orthophosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate, organic phosphide and phosphorus oxide; the copper source is selected from Cu (OAc)₂，CuSO₄，Cu(NO₃)₂，CuCl₂One or more of them.

6. The method according to claim 3, wherein the crystallization in step b) is performed in a static or dynamic state.

7. The method of claim 3, wherein said step a) includes R1/Al in the initial gel mixture₂O₃＝5.0～10。

8. The method of claim 3, wherein said step a) includes R2/Al in the initial gel mixture₂O₃＝0.25～1.0。

9. For NO_xA catalyst for selective reduction removal reaction, which is obtained by roasting the molecular sieve according to any one of claims 1-2 or the molecular sieve synthesized by the method according to any one of claims 3-8 in air at 550-700 ℃.